Simulation of Mechanical and Thermal Loads and Microtexturing of Ceramic Cutting Inserts in Turning a Nickel-Based Alloy

Round 1

Reviewer 1 Report

In this paper, EDM was used to create microtextures (microgrooves and microwells) on the rake face of TiN-coated  Si3N4 ceramic square inserts.  Mechanical and thermal loads were simulated for predicting the best among microgrooves and microwells. 

The following points are asked to incorporate into the current manuscript:

1. The authors have performed the simulation tests for turning Nickel base alloys. But the details of the workpiece and turning parameters are not specified clearly. Add a separate subsection and show the grade of nickel alloys, turning setup and machining parameters, and machining length.

2. Geometry details of the cutting tool are not provided. Add it clearly.

3. The authors have mentioned "Various textures were formed with a width of up to 50–150 µm, with a depth of up 294 to 20–30 µm, with a step of 150–300 µm on the faces of the inserts at a distance of 0.150– 295 0.175 mm."  in section 3.1. 

This creates a generalization sense. Clearly mentioned the groove size and well size used to create on tool-tip. Use a table for these details.

4. Provide the results table for response cutting force and flank wear. 

5. Are the authors done experiments on turning? If yes, provide the comparison chart or graph for experimental Vs. Simulation.

6. Why the authors have chosen ceramic insert? Also, explain the coated ceramic insert. 

7. It is known that the ceramic is highly brittle, hence tool-tip breakage can be easily possible due to high load and vibration. Hence, it is suggested to do a tool life assessment for better clarity towards sustainability.

8. Simulation part is inadequate, it must be informatics. Add the meshing size for the insert and workpiece.

9. Conclusion should be written point-wise. Also, add the future scope for the reader. 

10. Tool wear images are required.

11. Abstract should be more specific. add some important results in %. 

 

 

Extensive English language editing is required. 

Author Response

Response to Reviewer 1 Comments

Dear reviewer,

Thank you so much for your kind evaluation of our work. We agree with all your proposals and comments and have modified the manuscript accordingly.

We hope the manuscript will be suitable for publishing in Metals and attract many potential journal readers with your comments. The introduced corrections in the text of the manuscript are marked yellow.

 

Kind regards,

Authors.

Reviewer comments

Point 1: The authors have performed the simulation tests for turning Nickel base alloys. But the details of the workpiece and turning parameters are not specified clearly. Add a separate subsection and show the grade of nickel alloys, turning setup and machining parameters, and machining length.

Response 1: Thank you so much for your kind recommendation. It is mentioned in Subsection 2.6. Resistance Tests:

• the details of the workpiece – “A workpiece with a diameter of 100 mm was made of XH45MBTJuBP nickel-based heat-resistant alloy”;
  • grade of nickel alloys – “XH45MBTJuBP nickel-based heat-resistant alloy”, “This alloy is the analog of Inconel 718…” (the reference is provided for the chemical composition; if it is necessary, it can be repeated once again in the text of the manuscript);
• turning parameters – “A workpiece was machined on a ZMM CU500MRD lathe machine (ZMM, Nova Zagora, Bulgaria) as follows: cutting speed V = 300 m/min, feed s = 0.5 mm/rev and cutting depth t = 0.5 mm.”:
  • turning setup – “a ZMM CU500MRD lathe machine (ZMM, Nova Zagora, Bulgaria)”;
  • machining parameters – “cutting speed V = 300 m/min, feed s = 0.5 mm/rev and cutting depth t = 0.5 mm.”;
• machining length – up to the criterion of failure of 400 µm (the parameter is not length but time/operational life up to the criterion of failure).

 

Point 2: Geometry details of the cutting tool are not provided. Add it clearly.

Response 2: Thank you for pointing it out. It is mentioned in Subsection 2.2. Modeling of Mechanical and Thermal Loads. The relevant figure is added (Figure 1).

 

Point 3: The authors have mentioned "Various textures were formed with a width of up to 50–150 µm, with a depth of up 294 to 20–30 µm, with a step of 150–300 µm on the faces of the inserts at a distance of 0.150– 295 0.175 mm."  in section 3.1. 

This creates a generalization sense. Clearly mentioned the groove size and well size used to create on tool-tip. Use a table for these details.

Response 3: Thank you, the table is provided (Table 7).

 

Point 4: Provide the results table for response cutting force and flank wear.

Response 4: Thank you for pointing it out. In the frame of the current work, we did not measure the response cutting force for the experimental data approbation but only flank wear since our work aims to improve the operational life of the cutting tool made of oxide and nitride ceramics. However, our research group has significant experience in measuring cutting forces and even in adaptive cutting based on in-situ monitoring/diagnostic system that demonstrated an considerable effect in roughing:

1. Grigoriev, N.; Gurin, V.D.; Volosova, M.A.; Cherkasova, N.Y. Development of residual cutting tool life prediction algorithm by processing on CNC machine tool. Mater. Werkst. 2013, 44, 790–796.
2. Grigoriev, N.; Kozochkin, M.P.; Sabirov, F.S.; Kutin, A.A. Diagnostic systems as basis for technological improvement. Proc. CIRP 2012, 1, 599–604.
3. Grigoriev, N.; Sinopalnikov, V.A.; Tereshin, M.V.; Gurin, V.D. Control of parameters of the cutting process on the basis of diagnostics of the machine tool and workpiece. Meas. Tech. 2012, 55, 555–558.
4. Stebulyanin, M.; Ostrikov, E.; Migranov, M.; Fedorov, S. Improving the Efficiency of Metalworking by the Cutting Tool Rake Surface Texturing and Using the Wear Predictive Evaluation Method on the Case of Turning an Iron–Nickel Alloy. Coatings2022, 12, 1906.

The shown formulas (1-3) are based on the experimentally obtained data. The table with the measured flank wear data is provided (Table 9).

 

Point 5: Are the authors done experiments on turning? If yes, provide the comparison chart or graph for experimental Vs. Simulation.

Response 5: Thank you, the table is provided (Table 10). In our opinion, it is not informative since we did not measure tensile straight and deformations during cutting, and the modern simulation software is not available to imitate the wear process. However, it should be noted that the technological issues of microtexture production limit further comparisons. At this microscale, the production of microtextures on insulating ceramics is technologically limited, as seen in Figure 9. It was impossible to achieve a wide range of size groups by varying electrical discharge machining factors using a relatively universal tool and equipment and specially designed assisting measures for all the possible types of microtextures. Obviously, for a more detailed experimental study of the influence of the microtexture dimension type on the wear chamfer value and the tool's service life, the development of electrical discharge machining technology in the microscale and the appropriate tooling and equipment are required. The relevant passage is added.

 

Point 6: Why the authors have chosen ceramic insert? Also, explain the coated ceramic insert.

Response 6: Thank you, it is provided in the text of the manuscript:

• About the absence of studies related to the research of cutting ceramics mainly used for machining hard-to-machine metal alloys and hardened steels: “Meanwhile, one of the promising materials for machining modern aviation nickel-based heat-resistant alloys, hot-resistant anti-corrosion, and hardened steels, namely cutting ceramics (Si₃N₄, SiAlON, Al₂O₃, etc.), remain outside the due attention of the scientific community but is of practical interest to the industrial sector of the economy. As can be seen from the published works, mainly SiAlON [18,19], Al₂O₃+SiC [20], and Al₂O₃+TiC [21] ceramic tools are used in cutting nickel-based superalloys”;
• About an obstacle for electrical discharge machining of oxide and nitride ceramics: “The only obstacle to using high-performance electrical discharge machining methods in microtexturing the cutting inserts can be the absence of the electrical conductive properties of the oxide and nitride ceramics (such as SiAlON, Si₃N₄, Al₂O₃) that are used in producing the most wear resistant cutting insert for cutting heat-resistant materials mainly used in the aviation industry – nickel-based superalloys (gas turbine engines and other responsible parts of the airplanes subjected to the extreme operating conditions). However, the problem of machinability can be solved by innovative methods of electrical discharge machining of the insulating materials, which allows producing kerfs in the Al₂O₃ insulating ceramics kerfs with a depth of up to o 54.16 ± 0.05 µm with a thickness of the blank of up to 5.00 mm using a combined method of assisting electrode technique and powder-mixed electrical discharge machining [38,39].”;
• About the necessity of multifunctional conductive coating for insulating ceramics: “Assisting electrode technique uses additional conductive coating (self-adhesive tape, PVD-coating) to provide the conductive properties of the outer layer of the insulating workpiece to address there the initial electrical impulses and discharges when an underlayer of the workpiece is subjected to the thermochemical dissociation [43-45].”

It should be noted that any other conductive coating can be used to provide a conductivity of the outer layer on the surface of the insulating sample. Many works of our research group are devoted to it, proposing using Ni-Cr coating that can have an effect on electrical discharge machining ability for aluminum oxide or Cu-Ag multilayer sandwich also showed remarkable results:

1. Okunkova, A.; Volosova, M.A.; Kropotkina, E.Y.; Hamdy, K.; Grigoriev, S.N. Electrical Discharge Machining of Alumina Using Ni-Cr Coating and SnO Powder-Mixed Dielectric Medium. Metals 2022, 12, 1749.
2. Grigoriev, S.N.; Okunkova, A.A.; Volosova, M.A.; Hamdy, K.; Metel, A.S. Electrical Discharge Machining of Al₂O₃Using Copper Tape and TiO₂ Powder-Mixed Water Medium. Technologies 2022, 10, 116.
3. Okunkova, A.A.; Volosova, M.A.; Hamdy, K.; Gkhashim, K.I. Electrical Discharge Machining of Alumina Using Cu-Ag and Cu Mono- and Multi-Layer Coatings and ZnO Powder-Mixed Water Medium. Technologies2023, 11, 6.
4. Volosova, A.; Okunkova, A.A.; Fedorov, S.V.; Hamdy, K.; Mikhailova, M.A. Electrical Discharge Machining Non-Conductive Ceramics: Combination of Materials. Technologies 2020, 8, 32.
5. Volosova, M.; Okunkova, A.; Peretyagin, P.; Melnik, Y.A.; Kapustina, N. On Electrical Discharge Machining of Non-Conductive Ceramics: A Review. Technologies2019, 7, 55.
6. Grigoriev, S.N.; Hamdy, K.; Volosova, M.A.; Okunkova, A.A.; Fedorov, S.V. Electrical discharge machining of oxide and nitride ceramics: A review. Des. 2021, 209, 109965. https://doi.org/10.1016/j.matdes.2021.109965

Still, it can bring difficulties in cleaning samples after such coating when TiN-coating can be multifunctional, providing conductivity of the outer layer and positively affecting the operational life of the cutting tool. The relevant passage is added to the text of the manuscript (Subsection 2.5. Multifunctional Coating).

 

Point 7: It is known that the ceramic is highly brittle, hence tool-tip breakage can be easily possible due to high load and vibration. Hence, it is suggested to do a tool life assessment for better clarity towards sustainability.

Response 7: Thank you, this was exactly the justification for carrying out the wear tests described in Subsection 3.5. Wear Resistance of Microtextured Cutting Inserts:

Figure 11 (attachment). The average flank wear of TiN-coated Si₃N₄ cutting inserts on the cutting time in turning XH45MBTJuBP nickel-based heat-resistant alloy (V = 300 m/min, s = 0.5 mm/rpm, t = 0.5 mm).

“The experimental results confirm the modeling of the mechanical and thermal loads and demonstrate that the operational life of the TiN-coated Si₃N₄ cutting insert was improved by more than 1.3. The average durability of the cutting insert with microwells of ø80 µm exceeded 10 min in turning nickel-based heat-resistant alloy.”

We are open to the reviewer's suggestion if it is necessary to add something else to make it more understandable.

 

Point 8: Simulation part is inadequate, it must be informatics. Add the meshing size for the insert and workpiece.

Response 8: Thank you for pointing it out. Informatics is in using previously obtained equations (1-3) for simulations loads using standard software tools. Mesh was program generated, mesh type was standard, global size was 0.1256 mm, and accuracy was 0.0063 mm. The relevant sentence is added (Subsection 2.2. Modeling of Mechanical and Thermal Loads).

 

Point 9: Conclusion should be written point-wise. Also, add the future scope for the reader.

Response 9: Thank you. The conclusions are revised, and the future outlook is added.

 

Point 10: Tool wear images are required.

Response 10: Thank you. The tool wear images are provided in Figure 12.

 

Point 11: Abstract should be more specific. add some important results in %. 

Response 11: Thank you for your kind recommendation. The abstract has been revised.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. The paper is present the developement of wear-resistant ceramic cutting edge life, which requires high hardness and strenght during machining. A TiN coated Si4N4 tool was EDM machined to form microtextures on th surface to improve tool life. The mechanical and thermal stress of the tool during work was investigated by simulation. Based on the results, the approproate microtexture was selected, on the bases of which the lifetime of the tool increased 1,3 times.

The manuscript is clear and relevant for the field and is presented in well-structured manner. The novelity of the topic is the processing of microtexture with EDM and the use of simulation.

The authors should consider the effect of EDM on the tool surface quality and perform microscopic and micro hardness testing on the affected microstructure.

The conclusions partially answer the main question, but need to be supplimented with additional tests.

The cited references are monstly relevant and appropriate publications.

 

 

The article is nice and interesting with many references.

Some places should be improved:

- Table instead Table 2 (line: 154,157)

- Table 2 instead Table 3 (line:160,166)

- Table 3 instead Table 4 (line:177,181)

- Table 4 instead Table 5 (line: 188,198)

- Table 5 instead Table 6 (line 259,264)

- Table 6 instead Table 7 (line: 331,342).

Correct the gramatical errors in lines: 43,0143,0389.

Unify the dimensions of the figures.

It is not appropriate to use more then two-three references after a sentence, lines: 38,43,47,256, 261.

The conclusions could be more developed and detalied.

 

 

Author Response

Response to Reviewer 2 Comments

Dear reviewer,

Thank you so much for your kind evaluation of our work. We agree with all your proposals and comments and have modified the manuscript accordingly.

We hope the manuscript will be suitable for publishing in Metals and attract many potential journal readers with your comments. The introduced corrections in the text of the manuscript are marked green.

 

Kind regards,

Authors.

Reviewer comments

Point 1: The authors should consider the effect of EDM on the tool surface quality and perform microscopic and micro hardness testing on the affected microstructure.

The conclusions partially answer the main question, but need to be supplimented with additional tests.

Response 1: Thank you so much for your kind recommendation. In practice, optical microscopy is presented in Figure 9 a,b. It should be noted that this study is part of a project devoted to the research of the microtexture effect on the operational parameters of the cutting tool made of oxide and nitride ceramics in cutting hard-to-machine metal alloys (Ni- and Ti-based), hardened steels. Various research steps were planned within the project, including scanning electron microscopy and friction sliding. However, hardness tests are not included but can be easily realized. We would not present here other results to avoid overloading the manuscript with unnecessary data since it is already 24 pages but thankful to the reviewer for his idea that can be implemented for publishing further works. The relevant passage is added to the conclusions.

 

Point 2: Some places should be improved:

- Table instead Table 2 (line: 154,157)

- Table 2 instead Table 3 (line:160,166)

- Table 3 instead Table 4 (line:177,181)

- Table 4 instead Table 5 (line: 188,198)

- Table 5 instead Table 6 (line 259,264)

- Table 6 instead Table 7 (line: 331,342).

Response 2: Thank you for noticing it; it is revised.

 

Point 3: Correct the gramatical errors in lines: 43,0143,0389.

Response 3: Thank you for pointing it out; it is revised. If we did not get it correctly, we are open to revise them once again.

 

Point 4: Unify the dimensions of the figures.

Response 4: Thank you, we have found only in Deformations (Figure 5b), it is revised (µm instead of ×10^-3 mm). If other figures should be changed, we are open to modifying them.

 

Point 5: It is not appropriate to use more then two-three references after a sentence, lines: 38,43,47,256, 261.

Response 5: Thank you, it’s revised.

 

Point 6: The conclusions could be more developed and detalied.

Response 6: Thank you so much for your kind recommendation. The conclusions are revised.

Round 2

Reviewer 1 Report

The authors have made all necessary corrections in the revised manuscript. Now the paper can be accepted. 

Minor corrections are required.